Only load scripts and styles if a specific shortcode is present in the content when the page/post is saved

functions.php

/*
 * This first function maps shortcodes to their respective resources,
 * then checks whether those shortcodes exist in the content,
 * then stores the required resource handles in a custom field.
 * This way, we aren't running resource-intensive functions on every page load.
 */
function check_post_shortcodes($post_id) {

	// Map conditional shortcodes to their respective resource handle
	// Remember to manually dequeue resource handles below as well.
	$shortcodes_mapper = array(
		'vc_row' => 'js_composer_front',
	);


	// If this is a revision, get real post ID
	if ( $parent_id = wp_is_post_revision( $post_id ) ) 
		$post_id = $parent_id;


	// Get the post content
	$post = get_post($post_id);
	$content = $post->post_content;


	// Create an empty array for the required resource handles to be stored in post meta
	$required_resources = array();


	// For each shortcode handle in the array, search the content to see if it's present.
	// If it exists in the content, add it's resource handle to the list of required resources.
	foreach ( $shortcodes_mapper as $shortcode_tag => $resource_handle ) {
		if ( strstr($content, '[' . $shortcode_tag ) ) {
			array_push($required_resources, $resource_handle);
		}
	}


	// Only continue if we have any resource handles
	if ( $required_resources ) {

		// Encode the array to save in post meta
		$required_resources = json_encode($required_resources);

		// Unhook this function so it doesn't loop infinitely
		remove_action( 'save_post', 'check_post_shortcodes' );

		// If our custom field already exists, just update it
		if ( get_post_meta( $post_id, 'conditional_shortcode', true) ) {
			update_post_meta( $post_id, 'conditional_shortcode', $required_resources );
		} 
		// Otherwise, create it
		else {
			add_post_meta( $post_id, 'conditional_shortcode', $required_resources );
		}

		// NOTE: You may want to change the name of the custom field. Prefixing with an underscore will also hide it from the back end.

		// Re-hook this function
		add_action( 'save_post', 'check_post_shortcodes' );
	}

	// Finally, if our shortcode is not present, but our custom field does, delete the custom field
	else {
		if ( get_post_meta( $post_id, 'conditional_shortcode', true) ) {
			delete_post_meta( $post_id, 'conditional_shortcode' );
		}
	}
}
// This function only fires when the post is saved. Not on page load.
add_action( 'save_post', 'check_post_shortcodes' );


/*
 * This second function dequeues your conditional resources,
 * then re-enqueues the ones present in the custom field.
 */
function conditionally_load_shortcode_resources() {

	// Remember to manually dequeue your conditional resource handles in case they were already enqueued
	wp_dequeue_style( 'js_composer_front' );

	// Set up our variables
	global $post;
	$post_id = $post->ID;
	$resource_handles = get_post_meta( $post_id, 'conditional_shortcode', true);

	// If our array of handles exists, enqueue each one.
	if ( $resource_handles ) {
		foreach ( json_decode($resource_handles) as $handle ) {
			wp_enqueue_style( $handle );
		}
	}
}
add_action( 'wp_enqueue_scripts', 'conditionally_load_shortcode_resources', 100 );

hi
is there any updates to this, seems not working

when pasted into this plugin:

My Custom Functions
by Arthur Gareginyan

Oh hey @aelsharawi, I don't know why I never got an email from your comments.

Anyway, this Gist was mostly for demonstration purposes. You need to configure it a bit to make it work. There is an array on line 11 that needs takes a shortcode ('vc_row') and associates it to a resource handle ('js_composer_front'). There is also a manual resource dequeue on line 81 that would need to be edited.

Sorry it didn't work for you right out of the box. It is more of a proof of concept.

If you need a built out plugin for that, I would recommend Plugin Organizer or WP Asset CleanUp